Conventionally, there has been an indexable rotary cutting tool having a cylindrical tool body provided with a plurality of grooves extending from its proximal end toward its distal end in a peripheral surface of the tool body, each groove being configured to allow a plurality of cutting inserts to be removably mounted therein in a direction of the tool rotational axis. In general, the rotary cutting tool having such shape is called a roughing cutter. In the roughing cutter, since the plurality of cutting inserts is aligned in the direction of tool rotational axis, a substantial length of the cutting edges is large and the tool can therefore form large depth of cut. Accordingly, highly efficient machining can be achieved.
Patent Document 1 discloses a roughing cutter on which quadrangular cutting inserts each having a cutting edge having a wave shape in a side view are mounted. The cutting inserts are arranged such that: in a relationship in each groove, they are aligned with an interval therebetween in an axial direction; and in a relationship between the plurality of grooves, the cutting edges having a wave shape that are aligned in the axial direction form consecutive rows of cutting edges in a rotational trajectory around the axis. Patent Document 1 states that the wave shape cutting edges cause chips to be separated into smaller pieces than the length of the cutting edge, and therefore the disposal capacity of the chips can be improved.